Investors hunting for the biggest stock winners of 2026 might be surprised to learn they already own some of them — through small-cap ETFs they've held for months.
Five stocks in the Russell 2000 Index have each surged nearly 400% or more this year: Applied Optoelectronics Inc. (AAOI), Rackspace Technology, Inc. (RXT), Aehr Test Systems (AEHR), MaxLinear Inc. (MXL), and Agilon Health Inc. (AGL). They operate in completely different industries — optical networking, cloud services, semiconductor testing, connectivity chips, and healthcare — but several of them show up together in a handful of small-cap growth and broad-market ETFs.
This highlights something interesting about the AI trade in 2026: some of the strongest gains haven't come from mega-cap tech companies, but from smaller firms supplying optical networking equipment, semiconductor testing systems, and data-center connectivity products. The AI supply chain is expanding beyond Nvidia, and small caps are catching the wave.
The resurgence in these high-flying Russell 2000 names has also helped narrow the performance gap between small caps and large-cap technology stocks. For much of 2026, the Russell 2000 actually outperformed the Nasdaq-100 (which holds the largest tech names, including the Magnificent 7) as investors broadened their focus beyond the mega-cap AI trade. That trend began to reverse in early May as heavyweight technology stocks regained momentum. The Nasdaq-100 has since pulled ahead and is now up roughly 21% year-to-date, compared with about 16% for the Russell 2000.
Still, the strong performance of a handful of small-cap winners suggests investor appetite for AI-related opportunities extends well beyond the largest technology companies. That provides support for small-cap ETFs even as leadership shifts back toward the Nasdaq's biggest names.
Which ETFs Had Exposure to Multiple Winners?
Several ETFs show up repeatedly among the ownership lists of the year's top-performing Russell 2000 stocks.
The Vanguard Russell 2000 Growth ETF (VTWG) appears among the holders of Applied Optoelectronics, MaxLinear, and Agilon Health. The ProShares Ultra Russell 2000 (UWM) also holds positions in all three names. The iShares Russell 2000 Growth ETF (IWO) and Vanguard Russell 2000 ETF (VTWO) likewise gained exposure to Agilon Health and other small-cap outperformers through their benchmark allocations.
For investors who owned diversified small-cap growth funds at the start of the year, the gains from these stocks likely contributed meaningfully to performance despite relatively modest portfolio weightings. It's a reminder that sometimes the biggest winners are hiding in plain sight inside your ETF.
The AI Supply Chain Is Expanding Beyond Nvidia
Three of the five biggest Russell 2000 winners share a common thread: AI infrastructure.
Applied Optoelectronics manufactures optical networking products used in high-speed data-center connections. Aehr Test Systems supplies semiconductor burn-in and testing equipment. MaxLinear develops connectivity and networking chips used across communications infrastructure. Their rallies suggest investors are increasingly looking beyond chipmakers and into the broader ecosystem supporting AI deployment.
The trend has also started spilling into thematic funds. ETFs such as the Defiance AI & Power Infrastructure ETF (AIPO) were launched to capture companies benefiting from AI infrastructure spending, including data centers, networking equipment, and power systems that support AI workloads. Although that fund doesn't include the small-cap winners in its portfolio, it tracks other stocks closely associated with AI infrastructure.
Among other ETFs that track small- and micro-cap winners and are performing well this year:
Bottom Line
While NVIDIA Corp. (NVDA), Dell Technologies Inc. (DELL), and Micron Technology Inc. (MU) have dominated AI headlines in 2026, some of the market's largest gains have come from lesser-known Russell 2000 companies.
For ETF investors, the takeaway is simple: small-cap growth funds may have provided exposure to several of the year's biggest winners long before they became Wall Street's latest AI success stories. Sometimes the best trades are the ones you already have.
